<template>
  <div >
    <router-link v-show="showabs" tag="div" to="/" class="header-abd">
      <div class="iconfont icon-zuobian header-abdback-icon"></div>
    </router-link>

    <div
      class="header-fixed"
      v-show="!showabs"
      :style="opacityStyle"
    >
      <router-link to="/">
        <div
          class="iconfont icon-zuobian header-fixed-icon"

        ></div>
      </router-link>
      景点详情
    </div>
  </div>
</template>

<script>
export default {
  name: 'DetailHeader',
  props:{
    sightName:"",
    bannerImg:"",
    gallaryImgsd:[],
  },
  data() {
    return {
      showabs : true,
      opacityStyle:{
        cpacity:0
      }
    }
  },
  methods:{
    handleScroll(){
      const top = document.documentElement.scrollTop
      if( top > 60){
        /*若隐若现 的计算方法*/
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {opacity}
        this.showabs = false
      }else{
        this.showabs = true
      }
    }
  },
  activated() {
    window.addEventListener('scroll',this.handleScroll)
  },
  // 解绑全局事件
  deactivated() {
    window.removeEventListener('scroll',this.handleScroll)
  }
}
</script>

<style lang="stylus" scoped>
@import "~styles/varibles.styl"

.header-abd
  position absolute
  left .2rem
  top .2rem
  width .8rem
  height .8rem
  line-height .8rem
  border-radius .4rem
  text-align center
  background rgba(0, 0, 0, .8)

  .header-abdback-icon
    color #fff
    font-size .4rem

.header-fixed
  z-index 3
  position fixed
  top 0
  left 0
  right 0
  height $headerHeight
  line-height $headerHeight
  text-align center
  color #fff
  background $bgColor
  font-size .32rem

  .header-fixed-icon
    position absolute
    left 0
    top 0
    width .64rem
    text-align center
    font-size .4rem
    color #fff
</style>
